Simple double sqrt, pow

This is a simple programming, but I never really got how to do this.

Code:

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printf("Enter 5 doubles: ");
scanf("%lf %lf %lf %lf %lf", &a, &b, &c, &d, &e);
printf("v[] = {%11.3lf %11.3lf %11.3lf %11.3lf %11.3lf}\n\n", a,b,c,d,e);

length = double sqrt((double pow(double a,2) + double pow(double b,2) + double pow(double c,2) + double pow(double d,2) + double pow(double e,
2)));

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I'm trying to get the sum of the squares of a,b,c,d, and e, then square root that answer, but I never knew where to put the doubles and where not to (I always deleted, test, deleted, test, etc.). Can someone help me please? Much thanks!

pow and sqrt are overloaded to take doubles, floats and all sorts of integers even. So your program might be written:

Code:

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#include <stdio.h>
#include <math.h>

int main (void) {
    double a, b, c, d, e;
    fputs("Enter 5 decimals: ", stdout);
    scanf("%lf %lf %lf %lf %lf", &a, &b, &c, &d, &e);
   
    double sum_of_powers = pow(a, 2)
                        + pow(b, 2)
                        + pow(c, 2)
                        + pow(d, 2)
                        + pow(e, 2);
                       
    double length = sqrt(sum_of_powers);
   
    printf("The square root of the sum is %lf\n", length);
   
    return 0;
}

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Notice the lack of typecasting.